Eh, that's just how I saw it. Orin, Gortash and Ketheric already struggled to keep the Netherbrain under control pre-powerup, I didn't really get the impression Tav, become illithid or not, has it permanently in the bag. Hence the 3 months before it all just falls apart, starting from the most tangible threat: the army.
Someone's going to come and murder their way up the chain of command, just like we did it. Tav will probably die before the Netherbrain. It could escape, but I wager some bullshit plot device won't let it.
